Manual sanding of wooden articles is a slow process and has as an additional disadvantage that manual sanding, despite the best of intentions or skills, undesirably tends to round off square corners.
The sanding process can be expedited by mechanical movement of the sanding surface against the workpiece. Belt sanders are well known, as in U.S. Patents to Mooney, U.S. Pat. No. 3,482,358; Pollak, U.S. Pat. No. 3,538,650; and Johannsen, U.S. Pat. No. 4,628,640. Yet manual holding of the workpiece still tends to result in rounding of workpiece corners intended to be square--and accompanying unintended abrasion of fingertips, etc.
Examples of mechanized holding of repetitive workpieces are found in Crouch and Hoganson U.S. Pat. No. 5,092,081, and in Numao and Miyajima U.S. Pat. No. 5,179,805--especially where sanding of multiple curvatures is important. For simpler curve working, spindle sanders are used on drill presses reciprocated to even the wear on the sanding spindles. Automating such reciprocation is known, as pointed out by Ianuzzi in U.S. Pat. 4,821,457; and by Bill Krier in WOOD, The World's Leading Woodworking Magazine, September 1994, pp. 78-82.
My main interest focuses upon the sanding of plane surfaces by mechanically assisted manual holding of a workpiece in combination with effective mechanical moving of the workpiece as most desirable.